missing gosum entry for module providing package githubcomastaxiebeegovalidation imported by go-gin-exampleroutersapi; to add

You can try running the following command in your terminal:

go mod tidy

This should update your go.sum file with the missing entry for the module providing the package github.com/astaxie/beego/validation. If that doesn't work, you can try manually adding the following line to your go.sum file:

github.com/astaxie/beego/validation v2.0.1 h1:9gBZdLx8WtFw7VgZ3qjLb7cBkzRmV1YJp9lLeVd8u/I=

This assumes that version 2.0.1 is the version of the module that you need. If you need a different version, you can find the appropriate checksum by running go mod download for that version and looking at the corresponding line in the go.sum file.